The present invention relates to double file printed wiring board modules and, more particularly, to a double file printed wiring board module mounting printed wiring boards on both sides of an interconnect or side plane.
Double file printed wiring board modules are very well known to those skilled in the art. One type of double file printed wiring board module is described in U.S. Pat. No. 3,368,115, issued Feb. 6, 1968, to N. E. Hoffman in which is described a modular housing with improved interconnection means. Hoffman discloses a plurality of circuit boards, a pair of spaced apart circuit board connectors, and an interconnecting panel member which is wrapped around the circuit board connectors. Interconnections between different boards of the module are established by way of an edge contact on a first board which engages a feed through contact on one of the board connectors which, in turn, engages a conductor on the interconnecting panel. This conductor on the interconnecting panel extends to a second feed through contact which, in turn, engages an edge contact on a second printed wiring board.
Such an arrangement, while operating generally satisfactorily, includes circuit paths which are of inordinate length and contain several electrical connections. Electrical connections and long conductor lengths have been found to be a source of signal interference due to extraneous signal pick-up by the conductors and defects in continuity at conductor connection points. Further, the enclosed cubic construction can permit unacceptably high temperatures to exist during circuit operation.
U.S. Pat. No. 3,614,541, issued Oct. 19, 1971, to W. A. Farrand teaches construction of an electronic assembly comprising a plurality of modules having integrated circuits secured to the module boards. The module boards are interconnected, and further connected to output contacts through conducting strips formed on the interior of housing sides which support the module boards. The package is assembled by subjecting it to an environment which fuses the module output contacts to the conductive strips while simultaneously forming a hermetically sealed package. Such an arrangement, while operating generally satisfactorily, does not permit the replacement of individual module boards when a circuit failure is encountered. Additionally, the enclosed construction of the electronic assembly can permit build up of harmfully high temperatures on interior module boards.